181=r2

Solution for 181=r2 equation:

181=r2

We move all terms to the left:

181-(r2)=0

We add all the numbers together, and all the variables

-1r^2+181=0

a = -1; b = 0; c = +181;
Δ = b2-4ac
Δ = 02-4·(-1)·181
Δ = 724
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{724}=\sqrt{4*181}=\sqrt{4}*\sqrt{181}=2\sqrt{181}$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{181}}{2*-1}=\frac{0-2\sqrt{181}}{-2}
=-\frac{2\sqrt{181}}{-2}
=-\frac{\sqrt{181}}{-1}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{181}}{2*-1}=\frac{0+2\sqrt{181}}{-2}
=\frac{2\sqrt{181}}{-2}
=\frac{\sqrt{181}}{-1}
$